Molecular Cloning, Tissue Distribution and Segmental Ontogenetic Regulation of b0,+ Amino Acid Transporter in Lantang Pigs

  • Zhi, Ai-Min (College of Animal Science, South China Agricultural University) ;
  • Feng, Ding-Yuan (College of Animal Science, South China Agricultural University) ;
  • Zhou, Xiang-Yan (College of Animal Science, South China Agricultural University) ;
  • Zou, Shi-Geng (College of Animal Science, South China Agricultural University) ;
  • Huang, Zhi-Yi (College of Animal Science, South China Agricultural University) ;
  • Zuo, Jian-Jun (College of Animal Science, South China Agricultural University) ;
  • Ye, Hui (College of Animal Science, South China Agricultural University) ;
  • Zhang, Chang-Ming (College of Animal Science, South China Agricultural University) ;
  • Dong, Ze-Min (College of Animal Science, South China Agricultural University) ;
  • Liu, Zhun (College of Animal Science, South China Agricultural University)
  • Received : 2008.01.18
  • Accepted : 2008.03.07
  • Published : 2008.08.01


Cationic amino acid transporter $b^{0,+}AT$ (HGMW-approved gene symbol SLC7A9, solute carrier family 7, member 9) plays a crucial role in amino acid nutrition. In the present study, we describe the cloning and sequencing of porcine $b^{0,+}AT$. Based on the sequence of porcine $b^{0,+}AT$ deposited in the NCBI (National Center for Biotechnological Information), we identified a putative porcine homologue. Using rapid amplification of cDNA ends (RACE), the full-length cDNA encoding porcine $b^{0,+}AT$ was isolated. The porcine $b^{0,+}AT$ cDNA was 1,680 bp long, encoding a 487 amino acid trans-membrane protein. The predicted amino acid sequence was found to have 88.9% and 87.1% identity with human and mouse $b^{0,+}AT$, respectively. Real-time RT-PCR indicated porcine $b^{0,+}AT$ transcripts expressed in heart, kidney, muscle and small intestine. The small intestine had the highest $b^{0,+}AT$ mRNA abundance while the muscle had the lowest (p<0.05). Along the longitudinal axis, the ileum had the highest $b^{0,+}AT$ mRNA abundance while the colon had the lowest (p<0.05). The $b^{0,+}AT$ mRNA level was highest on day 7 and 90 in the duodenum (p<0.05). It increased from day 1 to day 26 in the jejunum (p>0.05) and had the highest abundance on day 60 (p<0.05). There was, however, no difference between day 1, 7, 26, 30, 90 and 150 (p>0.05). The strongest $b^{0,+}AT$ expression appeared on day 7 in the ileum before weaning, and then decreased till day 30 but rose gradually again from day 60 to 150 (p<0.05).


Supported by : Jiangxi Agricultural University


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